--- title: "Evidence: selenoprotein antioxidant plus CoQ10" description: "Supplementing with selenium and coenzyme Q10 improved thyroid function and related health outcomes in an elderly population with low selenium levels." url: "https://magellanlongevity.com/study/s134.md" canonical: "https://magellanlongevity.com/study/s134.html" html: "https://magellanlongevity.com/study/s134.html" type: "study" study_key: "s134" journal: "BMC Med" year: 2024 pmid: "38714999" doi: "10.1186/s12916-024-03411-1" citations: 1 updated: 2026-09-02 author: "Gabriel Radu, DO" author_credentials: "Physiatrist (PM&R). NY medical license 275110. NPI 1376861765." publisher: "Magellan Longevity" content_format: "markdown" --- # Evidence: selenoprotein antioxidant plus CoQ10 [Home](https://magellanlongevity.com/) › [Research map](https://magellanlongevity.com/longevity-research-map.html) › Evidence: selenoprotein antioxidant plus CoQ10 **HTML version:** https://magellanlongevity.com/study/s134.html · **In the Magellan app:** https://magellanlongevity.com/#/study/s134 ## Citation | Field | Value | | --- | --- | | Journal | BMC Med | | Year | 2024 | | PMID | [38714999](https://pubmed.ncbi.nlm.nih.gov/38714999/) | | DOI | [10.1186/s12916-024-03411-1](https://doi.org/10.1186/s12916-024-03411-1) | | Study key | s134 | ## Takeaway Supplementing with selenium and coenzyme Q10 improved thyroid function and related health outcomes in an elderly population with low selenium levels. ## The question Does supplementation with selenium and coenzyme Q10 affect thyroid hormonal status, cardiovascular (CV) mortality, and health-related quality of life (Hr-QoL) in individuals with insufficient selenium intake? ## Hypothesis Supplementation with selenium and coenzyme Q10 will have a beneficial effect on thyroid hormones, CV mortality, and Hr-QoL, particularly in individuals with low baseline selenium concentrations. ## Methods This was a randomized, placebo-controlled, double-blind study involving 414 individuals. Participants received either selenium yeast (200 µg/day) and coenzyme Q10 (200 mg/day) or a placebo for 48 months. Thyroid hormones (Free T3, free T4, reverse T3, TSH), CV mortality, and Hr-QoL (using SF-36) were measured at baseline and after the intervention. Statistical analyses included T-tests, repeated measures of variance, and ANCOVA. ## Results At baseline, individuals with the lowest selenium concentration had significantly higher TSH and lower fT3. After 4 years, supplementation significantly increased fT3 and rT3, decreased fT4, and diminished the increase in TSH levels compared with placebo (p = 0.03). In the placebo group, TSH and fT4 values above the median were associated with increased 10-year CV mortality (p < 0.04) and a decline in mental Hr-QoL, which was not observed in the active intervention group. ## Conclusion Supplementation with selenium and coenzyme Q10 had a beneficial effect on thyroid hormones, which was associated with improved CV mortality and Hr-QoL outcomes. The initial selenium deficiency in the elderly study population was linked to impaired thyroid function, and the observed changes in thyroid hormone levels are likely due to increased deiodinase activity. ## Limitations The study was retrospectively registered at ClinicalTrials.gov (NCT01443780) because registration was not mandatory when it began. ## Verbatim from the abstract > selenium and coenzyme Q had a beneficial effect with respect to cardiovascular mortality ## Reference 1. **Evidence: selenoprotein antioxidant plus CoQ10** BMC Med 2024 · [PMID 38714999](https://pubmed.ncbi.nlm.nih.gov/38714999/) · [DOI 10.1186/s12916-024-03411-1](https://doi.org/10.1186/s12916-024-03411-1) > selenium and coenzyme Q had a beneficial effect with respect to cardiovascular mortality ## Structured data ```json {"@context":"https://schema.org","@graph":[{"@type":"MedicalWebPage","@id":"https://magellanlongevity.com/study/s134.html#page","url":"https://magellanlongevity.com/study/s134.html","name":"Evidence: selenoprotein antioxidant plus CoQ10","description":"Supplementing with selenium and coenzyme Q10 improved thyroid function and related health outcomes in an elderly population with low selenium levels.","inLanguage":"en","isPartOf":{"@type":"WebSite","name":"Magellan Longevity","url":"https://magellanlongevity.com/"},"author":{"@type":"Person","name":"Gabriel Radu, DO","jobTitle":"Physiatrist (PM&R)","identifier":[{"@type":"PropertyValue","name":"NPI","value":"1376861765"},{"@type":"PropertyValue","name":"NY medical license","value":"275110"}]},"publisher":{"@type":"Organization","name":"Magellan Longevity","url":"https://magellanlongevity.com/"},"encoding":{"@type":"MediaObject","encodingFormat":"text/markdown","contentUrl":"https://magellanlongevity.com/study/s134.md"},"dateModified":"2026-09-02"},{"@type":"BreadcrumbList","itemListElement":[{"@type":"ListItem","position":1,"name":"Home","item":"https://magellanlongevity.com/"},{"@type":"ListItem","position":2,"name":"Research map","item":"https://magellanlongevity.com/longevity-research-map.html"},{"@type":"ListItem","position":3,"name":"Evidence: selenoprotein antioxidant plus CoQ10","item":"https://magellanlongevity.com/study/s134.html"}]},{"@type":"ScholarlyArticle","@id":"https://magellanlongevity.com/study/s134.html#study","name":"Evidence: selenoprotein antioxidant plus CoQ10","headline":"Evidence: selenoprotein antioxidant plus CoQ10","datePublished":"2024","isPartOf":{"@type":"Periodical","name":"BMC Med"},"identifier":"PMID:38714999","url":"https://pubmed.ncbi.nlm.nih.gov/38714999/","sameAs":"https://doi.org/10.1186/s12916-024-03411-1","abstract":"Supplementing with selenium and coenzyme Q10 improved thyroid function and related health outcomes in an elderly population with low selenium levels."}]} ``` ## Related on Magellan Longevity - [Longevity research map](https://magellanlongevity.com/longevity-research-map.html) - [Evidence-based longevity supplements](https://magellanlongevity.com/longevity-supplements.md) ## Scope and disclosures Educational information, not medical advice. Nothing here is intended to diagnose, treat, cure, or prevent any disease. Talk to your physician before starting any supplement or device, especially if you are pregnant, nursing, or taking medication. Editorial firewall: evidence grades are assigned from the published research and are independent of any affiliate commission. As an Amazon Associate, Magellan Longevity earns from qualifying purchases. Reviewed for accuracy by a board-certified physician (DO).